Articular cartilage, found at the ends of articulating bone in the body, is typically composed of hyaline cartilage, which has many unique properties that allow it to function effectively as a smooth and lubricious load-bearing surface. When injured, however, hyaline cartilage cells are not typically replaced by new hyaline cartilage cells. Healing is dependent upon the occurrence of bleeding from the underlying bone and formation of scar or reparative cartilage called fibrocartilage. While similar, fibrocartilage does not possess the same unique aspects of native hyaline cartilage and tends to be far less durable.
In some cases, it may be necessary or desirable to repair the damaged articular cartilage using an implant. While implants may be successfully used, the implant should have a shape substantially corresponding to the articular cartilage proximate the area where the implant is to be placed in order to maximize the patient's comfort, minimize damage to surrounding areas, and maximize the functional life of the implant.